1. Field of the Invention
The present invention relates to the field of kingpin locks in general, and in particular to a three piece locking arrangement for the kingpin or fifth wheel of a trailer or recreational vehicle.
2. Description of Related Art
As can be seen by reference to the following U.S. Pat. Nos. 3,982,413; 4,039,202; 4,141,233; 4,620,718; and 5,839,745, the prior art is replete with myriad and diverse kingpin locking arrangements that encircle the recessed portion of a conventional hitch pin.
While all of the aforementioned prior art constructions are more than adequate for the basic purpose and function for which they have been specifically designed, they are uniformly deficient with respect to their failure to provide a simple, efficient, and practical fifth wheel locking device which employs a collar and bar arrangement to surround the recessed portion of a trailer hitch pin. The clamp and bar arrangement are releasably engaged with one another via an offset lock mechanism.
As can be appreciated by reference to the above cited patents, a wide variety of kingpin locking devices have been developed to address the widespread threat of even very briefly unattended trailers being stolen both in broad daylight and even within view of a member of unsuspecting witnesses when the trailer is not provided with a fifth wheel locking device to prevent its unauthorized removal.
As a consequence of the foregoing situation, there has existed a longstanding need among trailer owners and tractor trailer operators for a new and improved fifth wheel locking device which is extremely simple to install and remove from a hitch pin, yet extremely difficult to remove by unauthorized individuals, and the provision of such a construction is a stated objective of the present invention.
Briefly stated, the fifth wheel locking device that forms the basis of the present invention comprises in general, a collar unit, a bar unit, and a locking unit for releasably engaging the bar unit relative to the collar unit.
As will be explained in greater detail further on in the specification, the collar unit of the preferred embodiment includes a generally U-shaped rigid collar member having a pair of legs which define an enlarged opening dimensioned to receive the recessed neck portion of a conventional hitch pin. The collar member is provided with a through bore formed in one leg and a pair of oppositely facing and overlapping counter bores formed in the other leg.
In addition, the bar unit comprises an elongated tempered steel bar member having a straight intermediate portion and inboard end dimensioned to be received through the through bore and one of the counterbores. The locking unit includes a lock member which is secured in one of the counterbores and provided with a rotatable lock catch element which is adapted to extend into the other counterbore to engage a peripheral recess formed on the inboard end of the bar member. The outboard end of the bar member is angled to provide a hand grip element to facilitate the insertion and removal of the bar member relative to the collar member.